Method of and apparatus for testing gas mixtures



Aug. 26 1924. 1,506,617

0. DOMMER METHOD OF AND APPARATUS FOR TESTING GAS MIXTURES Original Filed Oct. 11, 1920 In veni'or:

0. Dommr $5 I N, 1?. YmMa Patented Aug. 26, 1924.

PATENT OFFICE.

OTTO DOMMEB, O'F KABLSRUHE, GERMANY.

METHOD OF AND APPARATUS FOR TESTING GAS MIXTURES.

Application filed October 11, 1920, Serial No. 416,289. Renewed July 8, 1824.

To all whom it may concern:

Be it known that I, Or'ro DOMMER, a citizen of the German Republic, residing at Karlsruhe, Baden, whose ost-oflice address I is 16 Weltzienstrasse, l arlsruhe, Baden, Germany, have invented certain new and useful Improvements in the Methods of and Apparatus for Testing Gas Mixtures, of which the following is a specification.

My invention relates to improvements in the method of and apparatus for testing gas mixtures, and the object of the improvements is to provide a method and an apparatus in which absorption liquids for ascertaining the com onents of the gas are dispensed with. ll ith this object in view my invention consists in testing the gas by means of two properties thereof, viz, its viscosity and .its. specific gravity,- for which 20 purpose the gas is caused to flow through a. conduit comprising in succession a portion responding to differences of the viscosity of the gas such as'a capillary tube and a portion responding'to differences in the specific 86 gravity of the gas such as a nozzle, and the differential pressure between the capillary tube and the. nozzle is measured. In order that my invention be more clearly understood an example embodying the same will to be described hereinafter reference being had to the accompanying drawing and to the letters of reference marked thereon. In said drawing,

Fi l5 ing 51c principle of my improved method,

and

Fig. 2 is a diagrammatical view illustrat in my improved apparatus. a

efore describing my improved methed 40 in detail I shall at first explain the principle on which the method is based. Referring to Fig. 1, if a gas is made to flow in succession through a system consisting of a capillary tube 6 and a nozzle (1, between the said elements a differential pressure C is obtained which is a function of the resistances a and b and which may be expressed by the following formula:

1 is a diagrammatical view illustrat resistance of the gas flow' through the capilla tube 6 andthe nozz e a varies according y, the resistance of tube being changed as a function of the viscosity and that of the nozzle as a function of the density or specific gravity. Therefore the differential pressure C is changed by The change in pressure C+ZC can be ascertamed by means of a manometer connected to a branch pipe D, or it is continuously recorded.

In Fig. 2 I have shown in a diagrammatical way a preferred construction of the apparatus used for carrying out the method. The apparatus comprises a coarse filter (not shown), a fine filter F having an inlet :a and an outlet 7 for the gas to be tested, a conduit includin in series a capillary tube K and a nozzle a vacuum pump or the like connected at c (not shown), and a vacuum apparatus for maintaining a constant vacuum at the discharge side of the nozzle D As shown the said vacuum a paratus consists of an upright receptacle closed at its top and connected with the pipe (1 at al and a vertical tube c open at its top and passing into the receptacle U to a point near the bottom thereof. The receptacle is filled with a suitable liquid such as water, and it maintains a constant vacuum 12, within the pipe d which corresponds to the height of the column of liquid from the lower end of the pipe e to the surface of the water within the receptacle U as is indicated by the line 39 Tea part intermediate the nozzle D and the capillary tube K a manometer is connected which as shown consists of a. closed vessel N an open receptacle M connected with the vessel N by a pipe m, a float S disposed within the receptacle M and a recording device consisti of a stylus S connected with the fioat S in the manner to be described hereinafter. Within the vessel N, the pipe n,, and the receptacle there is a column of a suitable liquid, ordinarily water.

The operation of the apparatus so far described is as follows: The gas to be tested is admitted through the inlet 0:, and the vacuum pump connected to the piped at c is set in operation. The gas flows through the filters and is cleaned therein. There the capillary after it flows .successively through the capillary tube K and the nozzle D,, where its the stylus S on a rotary drum T shown conventionally on the drawing with a portion of the record produced 'by sa1dstylus.

In the method and'apparatus so far described the temperature and the pressure of the gas and the working pressure are assure of the gas vary continuousl dition the resistance of the puri ing'filter sumed to be constant, which condition, however, prevails only in,exceptional cases. For example, in case of flue gases being tested the chimney draught an the presor filters is different. If the di erenc'e of the at t e inlet to the capill'arytube K is 12,, the 'diiferential of the pressure is ($32 so that the total differential pressure between the ca illary tube and the nozzle is p l dp There ore com ensati'ng means must be provided in or er to correct the indication of the stylus S. In the example shown in the fi re such compensating means consist 0 a pi e 9 connected to the inlet end of the-capi lary tube K, and open to the atmosphere at which pipe includes two resistances pre erably in the form of capillary tubes W and W and is connected between the said tubes by a pipe g, with a compensating manometer to be described hereinafter.

The measurement based on the capillary tube K and the nozzle D is greatly influenced by the temperature, because the temerature coeflicient for the viscosity is diferent from that for the density. This influence is compensated by meansof a comvided b gensating gas such as air which is made to ow through a system similar to that prothe capillary tube K and the nozzle 1 and controlling a' compensating manometer cooperatin with the manometer N M,,. It will be un erstood that the temperature of the compensating gas must be the same as that of the gas to be tested.

The system for compensating the temperature is constructed as follows: WVithin 4 the filter F,.a filter F is located which has eter referred to above and comprising an In ad-.

pressures at the inlet to the system and upper closed vessel N and a lower open receptacle M connected by a pipen Within the vessel N 2 and receptacle M there is,

closed at its top and open'at its bottom,

and into the said chamber there extends the aforementioned pipe 9,. The floats S and S, are connected with the stylus S by means of chains or ropes 'v and w trained on rollers m, m o, p, g and r, the float S being suspended from the rope V and the roller p,

and the float S being suspended fromthe roller m by means of the rope w. The rope.

'0 which is trained on the larger roller m rollers 0, g, and r carries at its ends-weights Z and t and the stylus S, which weights are balanced by the float S The rollers m and m are rigidly connected with each ogher, and their diameter are at the ratio 0 2:1. I

The cooperation of the manometers will now be understood. The com osit'ron of the gas isrecorded by means of t e manometer N M the float'S setting the stylus S on the drum T. If now, the temperature of the gas is changed, the pressure between the capillary tube K, and the nozzle D is chan ed, so that the float S is displaced, which displacement is compensated by means of the capillary tube K, and the nozzle D, and the manometer N M,, S,. For example, if the float S is raised, the float S is raised the same amount. The displacement of the weight Z and the ro e n is the double of that of the float S ut when pulling the rope 'v with the weight Z a certain amount the roller p and float S are raised one halfthe amount. Therefore, the displacements of the floats S, and

S result only in a displacement of the ropes o and w and the weight Z, while the position of the stylus S is not altered.

In a similar way a variation of the pressure of the gas is compensated. For example, if the pressure of the gas is increased, the float S rises. However, at the same time the pressure of the air between the resistances W and W is increased, which pressure is transmitted to the chamber h. Therefore the float S rises, and this disglacement compensates the rise of the float f 1n the same way as has been described beore.

Preferably the weight Z is slightly heavier than the weight It. This excess of weight amounts to about one third of a grain more or less (twenty milligrams) which is sufficient to compensate the friction of the rope upon the rollers m, 0, p, q, and r. The rope or cord 'w is attached to the smaller or inner roller m, preferably by means of a pin or the like, not shown on the drawin Both the floats S and S are hollow, an they are so adjusted as to freely be afloat upon the surface of the liquid in the manometer or pressure gauge. Then a chan e occurs in the composition of the gas to tested, it will affect the gauge or manometer system N, M and the float S through the system K D If this chan e in composition should result in the rise 0 the float S only the stylus at will descend, and the rollers p, 'r are moved. The.rollers o and m wil not be moved, because the float .S' is retained in its osition b the surface tension of the liquid inside an outside of the same which the small excess of weight at 1 cannot overcome quick enough. Inasmuch as about one thousand milligrams or 15 /2 grains would be required to raise the float one millimeter (about 4 hundredths of an inch) at an im- "mersed sectional area of about ten square centimeters (about 1% s inch) it is obvious that the rise and fa of the weight S will result in the corresponding opposite movement of the indicating stylus S, while the weight S is ordinarily prevented from immediately following the movement of the float S On the other hand, if the tem erature of the gas and of the air admitte for compensating purposes are changed in consequence of a change in the temperature of the room, these variationswill alfect simultaneously both the system K D, as well as the system K D, and the pressure gauges or manometers N M, and N M will accordingly be correspondingly affected in the same manner, and the floats S and S are raised or lowered both the same amount. If

for instance, the temperature is increased, the float S will be raised. The indicating stylus ts is, however, unable to descend on account [of the upward movement of the float S which causes a translation of the movement of the roller p by means of the rollers o, m, and m instead of by way of the rollers and 1', so that changes of temperature will not aflect the position of the indicating stylus. The compensation of the pressure p acting upon the gas to be tested, takes place in a similar manner. A lowering of the pressure, for instance, will result-in a corresponding descent of the float S at the same time, however, and for the same amount ,as in the system K D the pressure of the compensating air between the resistances W and W will be reduced, causing a corresponding movement of the hollow body h, the size and area of which are so adjusted as to cause the float S to descend for the same value as the float S so that the compensation or correction for the influence of changes of pressure is effected in the same manner as indicated above with reference to the compensation for variations of temperature.

In the same way also such variations of the ressure are compensated which are caused y the vacuum pump connected at 0 draw- -its viscosity, ,an

ing difierent amounts of air through the vacuum apparatus U, which variations are in no case large. movements of the floats S and S which take place in the same'direction and simultaneously, are compensated. The working pressure p can therefore vary within the limits which are determined by the manometer structure. The liquid column, there fore, need not be kept constant by means of an overflow device.

As compared with most of the methods hitherto known, the method hereinbefore described has the advantage that it permits the characteristics or the constants of the gas mixture to be tested (absorption, combustion) to be determined without any preliminary alteration being required. Therefore, also such gases can be tested which do not contain a constituent which varies easily, either chemically or physically and the variation of which it has been customary to detearmine in previous gas determining metho s.

Moreover, the method according to the present invention permits a continuous indication, in contradistinction to the usual apparatus, and also-very rapid indication, as the consumption may be of any desired value, in contradistinction to methods in which absorption is employed. The latter necessitates a comparatively small consumption, in order not to be compelled to renew too I claim:

1. The herein described method of testing gas mixtures, which consists in causing by means of a pressure difference a flow of the gas to be tested through a conduit comprislng in succession a ortion mechanically reacting upon the gas by reason'of its visoften the means of absorption.

Generally speaking any cosity, and a portion, mechanically reacting upon the gas by means of its specific gravity, and measuring the pressure of the gas between said portions.

2. The herein described method of testing gas mixtures, which consists in causing by means of a pressure difference a flow of the gas to be tested through a set of a capillary tube and a nozzle arranged in series, and measuring the pressure of the gas between said nozzle and capillary tube.

.3. The herein described method of testing gas mixtures, which consists in causing by means of a pressure difference a flow of the gasto be tested through a main conduit comprising in succession a portion mechanically reacting u on the gas by reason of a portion, mechanically reacting upon the gas by means of its specific gravity, causing a flow of a compensating gas of constant chemical and physical state to the inlet end of said main conduit and through a compensating conduit comprising in succession two resistances,

and measuring a value which is a resultant of the pressures respectively between said portions and between said resistances.

4. The herein described method of testing gas mixtures, which consists in causing by means of a pressure difference a flow 'of the gas to be tested through a set of a capillary tube and a nozzle arranged in series, causing a flow of a gas of constant chemical and physical state to the gas to be tested through a pair of successive additional capil ary tubes, and measuring a value which is a resultant of the pressures respectively between said capillary tube and nozzle and said additional capillary tubes.

5. The herein described method of testing gas mixtures, whiclrconsistsin causing by means of a pressure difference a flow of the gas to be tested through a main conduit comprising in succession a portion mechanically reacting upon the gas by reason of its viscosity, and a portion, mechanically reacting'upon the gas by means of its specific gravity, causing a flow of a gas 0 a temperature equal to that of the gas to be ,tested through a compensating conduit comprising in succession a portion and measuring a value which is a resultant of the pressures of the gases between said portions in each of saidconduits.

6. The herein described method of testing gas mixtures which consists in causing by means of a pressure difference a flow of the gas to be tested through a set of a capillary tube and a nozzle arranged in series, causing a flow of agas of a temperature equal to that of the gas to be tested through a subsidiary set of a capillary tube and a nozzle, and measuring a value which is a resultant of the pressures of the gases between each of said nozzles and capillary tubes.

7. The herein described method of testing gas mixtures which consists in causing by means of a pressure difference a flow of the gas to be tested through a set of a capillary tube and a'nozzle arranged in serles, causing a flow of a gas of a temperature equal to that of the gas to be tested through a su sidiary set of a capillary tube and a nozzle, causing-a flow of a gas of constant hysical and chemical state to the gas to he tested through a pair of successive additional capillary tubes, and measuring a value which is a resultant of the pressures of the said gases between each of said sets of capillary tubes and nozzles and said pair of capillary tubes. T

8. The method of testing gases which consists in submitting the gas at different stages to reactions operating upon the gas by its viscosity and by its specific gravity respectively, and determining the change produced in the as between the said stages.

9. The metho' of testing and treating gases which consists in submitting said as to capillary action, and to a sudden drop of pressure in different stages, and determining the change produced between said stages. I

10. The method of testing gases which consists in first submitting said gas to frictional resistance, and at a distance from said resistance to a drop ofpressure, and determining the change produced in the interval between the two treatments.

11. The method of testing and treatin gases which consists in submitting sai gases to a frictional stage, and to an 'effiux stage, and determining the change produced between the two stages 12. The method of testing and of treating gases which consists in submitting said gases to a frictional stage and to an efllux stage, submitting another gas of unchangeable composition and pressure to different stages of frictional resistance, determining the change produced in said second gas between said resistances, causing said second gas to unite with the first mentioned gas before the treating stages of the first men tioned gas, and determining the .change produced in. the first mentioned gas between the treating stages.

18. The method of testing and of treating gases which consists in submittin said gas to a frictional stage and to an e ux stage, submitting another gas of substantially unchangeable composition and pressure to a frictional stage and to an eiflux stage, measuring the change produced in each of said gasesbetween the different stages, and causing the gases to unite after the efflux stage.

14:. The method of testing and treating gases WhlC-h consists in submitting the gases to a frictional stage and to an effiux sta e in succession, submitting another gas of su stantially unvarying pressure and composition to :a frictional stage and to an efliux stage, determining the change produced in each of said gases between the succeeding stages, and causing said gases to unite after the efiiux stages, submitting an additional supply of a gas of substantially unvarying pressure and composition to frictional resistiince in different stages, measurin the change produced in said last mentioned supply of, gas between said frictional stages, and causing said. last mentioned gas after said frictional stages to become united with the gas to be tested previous to its passing through the frictional and the efflux stages.

15. A system of testingand treating gases which consists of capillary means and of efHuX means at a distance from each other,

a pressure manometer between said stages,

and an axially displaceable indicator connected to said manometer, additional capillary means and efilux means in spaced relation to each other, and connected to temperature equalizing means, tubular connecting means between the two efilux means, pressure manometers intermediate each of the eifiux and capillary means, an additional gas conduit connected to the free end of the capillary means first mentioned, capillary means at a distance from each other in said last mentioned gas conduit, and a gas pressure manometer intermediate the capillary means last mentioned, and means to prevent the axial displacement of said indicator by chaiiges of pressure and of temperature.

16. A system for testing gas mixtures, comprising a conduit having in succession a portion mechanically reacting upon the gas by reason of its viscosity, and a portion, mechanically reacting upon the gas by means of its specific gravity, means to cause a flow of the gas to be tested successively through said portions, and means to measure the pressure of the gas between said portions.

17. A system for, testing gas mixtures, com rising a set of a capillary tube and a nozz e, means to cause a flow of the gas to be tested successively through said capillary tube and nozzle, and means to measure the pressure between said capillary tube and nozzle.

18. A system for testing gas mixtures, comprising a main conduit having in succession a portion mechanically reacting upon the gas by reason of its viscosity, and a portion, mechanically reacting upon'the gas by means of its specific gravity, means to cause a flow of the gas to be tested successively through said portions, a compensating conduit communicating at one end with the inlet end of said main conduit and having at its opposite end an admission of a gas of constant pressure and comprising a pair of resistances, and means to measure a value which is a resultant of the pressures of the gases respectively between said portions and resistances.

19. A system for testing gas mixtures, comprising a set of a capillary tube and a nozzle, means to cause a flow of the gas to be tested successively through said capillary tube and nozzle, a conduit communicating at one end with the inlet end of said capillary tube and having at its opposite end an inlet for a gas of constant pressure and comprising a pair of resistances intermediate its ends, and means to measure a value which is a resultant of the pressures of the gases respectively between said capil lary tube and nozzle and between said resistances.

20. A system for testing gas mixtures, comprising two sets each consisting of a portion mechanically reacting upon the gas by reason of its viscosity, and a portion,

mechanically reacting upon the gas by means of its specific gravity, disposed in series, meansto cause a flow of the gas to be tested through one of said sets and to cause a flow of a subsidiary gas of constant chemical composition through the other set, means to equalize the temperatures of said gases supplied to said sets, and means to measure a value which is a resultant of the pressures of said gases between the portions of each of said sets.

21. A system for testing gas mixtures, comprising two sets each consisting of a capi lary tube and a nozzle disposed in series, means to cause a flow of the gas to be tested through the capillary tube and nozzle of one of said sets and to cause a flow of a subsidiary gas of constant chemical composition through the capillary tube and nozzle of they other set, means to e ualize the temperatures of said gases supplied to said sets, and means to meausre a value which is a resultant of the pressures of said gases respectively between the capillary tube and nozzle of said sets.

'22. A system for testing gas mixtures, comprising a main conduit having in succession a portion mechanically reacting upon the gas by reason of its viscosity, and a portlon, mechanically reacting upon the gas by means of its specific gravity, means to cause a flow of the gas to be tested successively through said portions, a compensating assage communicating at one end with the inlet end of said conduit and having at its opposite end an inlet for a gas of constant pressure and comprising a pair of resistances, two manometers one acted u on by the pressure of the gas between said portions and the other one acted upon by the pressure between said resistances intermediate its ends, and indicating means under combined control by said manometers.

23. A system for testing gas mixtures, comprising a main conduit comprising a portlon adapted to respond to differences in the tenacity of gases and a portion res 0nding to difierences in the specific weig t of gases, means to cause a flow of the gas to be tested successively through said portions, a temperature compensating conduit comprising a portion adapted to respond to differences in the tenacity of gases and a portion responding to differences in the specific weight of gases. means to cause a flow of a gas of constant chemical state successively through said portions of the temperature compensating conduit, means to equalize the temperatures of the gases supplied to said conduits, a pressure compensating conduit connected at one end with the inlet end of said main conduit and having at its other end an inlet for a gas under constant pressure and comprising two resistances in series intermediate its ends, a liquid manometer connected with said main condnit between pr sur ch mber and the pressure comthe portlons thereof, a compensating llqnld pensatlng condult, and indicating means nmnometer connected with said compensatunder c0n o1nt control by sald manometers.

iIlfI conduit between the portions thereof and OTTO DOMMER. [L. 8.] 5 having a float provided with a pressure In the presence ofchamber constructed to vary the buoyancy of MAURICE W. ALTOFFER,

said float, a tubular connection between said F. H. REDIKER. 

